1. Field of the Invention
The present invention relates to a system and method for generating a simultaneous mixed audio output through a single output interface, particularly for use in an automated telephone information and/or Interactive Voice Response (“IVR”) system.
2. Background Art
It is well known to use concatenated voice prompts as the audio output in automated telephone information and/or IVR systems. In doing so, only one sound file in a string of sound files plays at any one time. As a result, there is a tendency for abrupt changes in the concatenated playback to be very noticeable.
FIG. 1 is a simplified block diagram of a prior art system and method for generating concatenated voice prompts in an automated telephone information and/or IVR system, denoted generally by reference numeral 10. As is well known in the art, such a system and method is typically embodied in automated telephone information and IVR systems in the form of a computer to telephone interface card.
As seen in FIG. 1, hardware manufacturers of interface cards for such telephone and IVR systems provide only a single data port or address (12) for receiving audio data (18). That data port (12) is accessed by a main processor or control logic (not shown), which subsequently transmits the data through a single output interface over a phone line (14) after the conventional processing required to do so by converter (16). As those of ordinary skill will appreciate, converter (16) may be a digital-to-analog converter or a format converter (single data channel into a multiplexed data channel), depending on whether phone line (14) has an analog or digital format.
As is readily apparent to those of ordinary skill, if two or more audio signals are to be mixed together for use in such a system and method, the data for the two signals must be mixed in advance. That is, the audio data from the two signals must first be mixed, and it is the resulting mixed audio data that is sent to the single data port (12) of the interface card. Such an advance mixing operation generally takes a significant amount of main processor time. Moreover, such advance mixing must also typically be performed on complete sound files before sending the completed mixed file to data port (12) of the interface card. As a result, such advance mixing is not a real-time operation.
For the foregoing reasons, there is a need for an improved computer to telephone interface card and associated method that overcomes the limitations of the prior art.